* {
    margin: 0;
    padding: 0;
}

header {
    height: 80px;
    line-height: 80px;
    color: aliceblue;
    display: flex;
    background-color: royalblue;
}

header h1 {
    line-height: 80px;
    margin-bottom: 0;
    color: aliceblue;
    display: flex;
}

nav .nav-link {
    padding-top: 0;
    padding-bottom: 0;
    display: inline;
    color: #ffffff;
}

a,
img {
    border: 0;
}

body {
    font: 16/180% Arial, Helvetica, sans-serif, "微软雅黑", "黑体";
    background: #eee;
    text-align: center;
}

table {
    border-collapse: collapse;
    border-spacing: 0;
}

td,
th {
    padding: 0;
}

.clear {
    clear: both;
}

.clear:after {
    content: "";
    display: table;
    clear: both;
}